/*
 * Licensed under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.gearpump.metrics

import io.gearpump.cluster.MasterToClient.HistoryMetricsItem

/**
 * Aggregates a larger set of metrics into a smaller set
 *
 * Sub Class must implement a constructor with signature like this:
 * MetricsAggregator(config: Config)
 */
trait MetricsAggregator {
  def aggregate(options: Map[String, String], inputs: Iterator[HistoryMetricsItem])
  : List[HistoryMetricsItem]
}